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libvirt/src/lxc/lxc_container.c
Daniel P. Berrange a4b57dfb9e Convert 'int i' to 'size_t i' in src/lxc/ files 
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-10 17:55:16 +01:00

2201 lines
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/*
* Copyright (C) 2008-2012 Red Hat, Inc.
* Copyright (C) 2008 IBM Corp.
*
* lxc_container.c: file description
*
* Authors:
* David L. Leskovec <dlesko at linux.vnet.ibm.com>
* Daniel P. Berrange <berrange@redhat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <unistd.h>
#include <mntent.h>
#include <sys/reboot.h>
#include <linux/reboot.h>
/* Yes, we want linux private one, for _syscall2() macro */
#include <linux/unistd.h>
/* For MS_MOVE */
#include <linux/fs.h>
#if WITH_CAPNG
# include <cap-ng.h>
#endif
#if WITH_BLKID
# include <blkid/blkid.h>
#endif
#if WITH_SELINUX
# include <selinux/selinux.h>
#endif
#include "virerror.h"
#include "virlog.h"
#include "lxc_container.h"
#include "viralloc.h"
#include "virnetdevveth.h"
#include "viruuid.h"
#include "virfile.h"
#include "virusb.h"
#include "vircommand.h"
#include "virnetdev.h"
#include "virprocess.h"
#include "virstring.h"
#define VIR_FROM_THIS VIR_FROM_LXC
/*
* GLibc headers are behind the kernel, so we define these
* constants if they're not present already.
*/
#ifndef CLONE_NEWPID
# define CLONE_NEWPID 0x20000000
#endif
#ifndef CLONE_NEWUTS
# define CLONE_NEWUTS 0x04000000
#endif
#ifndef CLONE_NEWUSER
# define CLONE_NEWUSER 0x10000000
#endif
#ifndef CLONE_NEWIPC
# define CLONE_NEWIPC 0x08000000
#endif
#ifndef CLONE_NEWNET
# define CLONE_NEWNET 0x40000000 /* New network namespace */
#endif
/* messages between parent and container */
typedef char lxc_message_t;
#define LXC_CONTINUE_MSG 'c'
typedef struct __lxc_child_argv lxc_child_argv_t;
struct __lxc_child_argv {
virDomainDefPtr config;
virSecurityManagerPtr securityDriver;
size_t nveths;
char **veths;
int monitor;
char **ttyPaths;
size_t nttyPaths;
int handshakefd;
};
static int lxcContainerMountFSBlock(virDomainFSDefPtr fs,
const char *srcprefix);
/*
* reboot(LINUX_REBOOT_CMD_CAD_ON) will return -EINVAL
* in a child pid namespace if container reboot support exists.
* Otherwise, it will either succeed or return -EPERM.
*/
ATTRIBUTE_NORETURN static int
lxcContainerRebootChild(void *argv)
{
int *cmd = argv;
int ret;
ret = reboot(*cmd);
if (ret == -1 && errno == EINVAL)
_exit(1);
_exit(0);
}
static
int lxcContainerHasReboot(void)
{
int flags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|
CLONE_NEWIPC|SIGCHLD;
int cpid;
char *childStack;
char *stack;
char *buf;
int cmd, v;
int status;
char *tmp;
if (virFileReadAll("/proc/sys/kernel/ctrl-alt-del", 10, &buf) < 0)
return -1;
if ((tmp = strchr(buf, '\n')))
*tmp = '\0';
if (virStrToLong_i(buf, NULL, 10, &v) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Malformed ctrl-alt-del setting '%s'"), buf);
VIR_FREE(buf);
return -1;
}
VIR_FREE(buf);
cmd = v ? LINUX_REBOOT_CMD_CAD_ON : LINUX_REBOOT_CMD_CAD_OFF;
if (VIR_ALLOC_N(stack, getpagesize() * 4) < 0)
return -1;
childStack = stack + (getpagesize() * 4);
cpid = clone(lxcContainerRebootChild, childStack, flags, &cmd);
VIR_FREE(stack);
if (cpid < 0) {
virReportSystemError(errno, "%s",
_("Unable to clone to check reboot support"));
return -1;
} else if (virProcessWait(cpid, &status) < 0) {
return -1;
}
if (WEXITSTATUS(status) != 1) {
VIR_DEBUG("Containerized reboot support is missing "
"(kernel probably too old < 3.4)");
return 0;
}
VIR_DEBUG("Containerized reboot support is available");
return 1;
}
/**
* lxcContainerBuildInitCmd:
* @vmDef: pointer to vm definition structure
*
* Build a virCommandPtr for launching the container 'init' process
*
* Returns a virCommandPtr
*/
static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef)
{
char uuidstr[VIR_UUID_STRING_BUFLEN];
virCommandPtr cmd;
virUUIDFormat(vmDef->uuid, uuidstr);
cmd = virCommandNew(vmDef->os.init);
if (vmDef->os.initargv && vmDef->os.initargv[0])
virCommandAddArgSet(cmd, (const char **)vmDef->os.initargv);
virCommandAddEnvString(cmd, "PATH=/bin:/sbin");
virCommandAddEnvString(cmd, "TERM=linux");
virCommandAddEnvString(cmd, "container=lxc-libvirt");
virCommandAddEnvPair(cmd, "container_uuid", uuidstr);
virCommandAddEnvPair(cmd, "LIBVIRT_LXC_UUID", uuidstr);
virCommandAddEnvPair(cmd, "LIBVIRT_LXC_NAME", vmDef->name);
if (vmDef->os.cmdline)
virCommandAddEnvPair(cmd, "LIBVIRT_LXC_CMDLINE", vmDef->os.cmdline);
return cmd;
}
/**
* lxcContainerSetStdio:
* @control: control FD from parent
* @ttyfd: FD of tty to set as the container console
*
* Sets the given tty as the primary conosole for the container as well as
* stdout, stdin and stderr.
*
* Returns 0 on success or -1 in case of error
*/
static int lxcContainerSetStdio(int control, int ttyfd, int handshakefd)
{
int rc = -1;
int open_max;
int fd;
if (setsid() < 0) {
virReportSystemError(errno, "%s",
_("setsid failed"));
goto cleanup;
}
if (ioctl(ttyfd, TIOCSCTTY, NULL) < 0) {
virReportSystemError(errno, "%s",
_("ioctl(TIOCSTTY) failed"));
goto cleanup;
}
/* Just in case someone forget to set FD_CLOEXEC, explicitly
* close all FDs before executing the container */
open_max = sysconf(_SC_OPEN_MAX);
for (fd = 0; fd < open_max; fd++)
if (fd != ttyfd && fd != control && fd != handshakefd) {
int tmpfd = fd;
VIR_MASS_CLOSE(tmpfd);
}
if (dup2(ttyfd, 0) < 0) {
virReportSystemError(errno, "%s",
_("dup2(stdin) failed"));
goto cleanup;
}
if (dup2(ttyfd, 1) < 0) {
virReportSystemError(errno, "%s",
_("dup2(stdout) failed"));
goto cleanup;
}
if (dup2(ttyfd, 2) < 0) {
virReportSystemError(errno, "%s",
_("dup2(stderr) failed"));
goto cleanup;
}
rc = 0;
cleanup:
VIR_DEBUG("rc=%d", rc);
return rc;
}
/**
* lxcContainerSendContinue:
* @control: control FD to child
*
* Sends the continue message via the socket pair stored in the vm
* structure.
*
* Returns 0 on success or -1 in case of error
*/
int lxcContainerSendContinue(int control)
{
int rc = -1;
lxc_message_t msg = LXC_CONTINUE_MSG;
int writeCount = 0;
VIR_DEBUG("Send continue on fd %d", control);
writeCount = safewrite(control, &msg, sizeof(msg));
if (writeCount != sizeof(msg)) {
goto error_out;
}
rc = 0;
error_out:
return rc;
}
/**
* lxcContainerWaitForContinue:
* @control: Control FD from parent
*
* This function will wait for the container continue message from the
* parent process. It will send this message on the socket pair stored in
* the vm structure once it has completed the post clone container setup.
*
* Returns 0 on success or -1 in case of error
*/
int lxcContainerWaitForContinue(int control)
{
lxc_message_t msg;
int readLen;
VIR_DEBUG("Wait continue on fd %d", control);
readLen = saferead(control, &msg, sizeof(msg));
VIR_DEBUG("Got continue on fd %d %d", control, readLen);
if (readLen != sizeof(msg)) {
if (readLen >= 0)
errno = EIO;
return -1;
}
if (msg != LXC_CONTINUE_MSG) {
errno = EINVAL;
return -1;
}
return 0;
}
/**
* lxcContainerSetID:
*
* This function calls setuid and setgid to create proper
* cred for tasks running in container.
*
* Returns 0 on success or -1 in case of error
*/
static int lxcContainerSetID(virDomainDefPtr def)
{
/* Only call virSetUIDGID when user namespace is enabled
* for this container. And user namespace is only enabled
* when nuidmap&ngidmap is not zero */
VIR_DEBUG("Set UID/GID to 0/0");
if (def->idmap.nuidmap && virSetUIDGID(0, 0) < 0) {
virReportSystemError(errno, "%s",
_("setuid or setgid failed"));
return -1;
}
return 0;
}
/**
* lxcContainerRenameAndEnableInterfaces:
* @nveths: number of interfaces
* @veths: interface names
*
* This function will rename the interfaces to ethN
* with id ascending order from zero and enable the
* renamed interfaces for this container.
*
* Returns 0 on success or nonzero in case of error
*/
static int lxcContainerRenameAndEnableInterfaces(bool privNet,
size_t nveths,
char **veths)
{
int rc = 0;
size_t i;
char *newname = NULL;
for (i = 0; i < nveths; i++) {
if (virAsprintf(&newname, "eth%zu", i) < 0) {
rc = -1;
goto error_out;
}
VIR_DEBUG("Renaming %s to %s", veths[i], newname);
rc = virNetDevSetName(veths[i], newname);
if (rc < 0)
goto error_out;
VIR_DEBUG("Enabling %s", newname);
rc = virNetDevSetOnline(newname, true);
if (rc < 0)
goto error_out;
VIR_FREE(newname);
}
/* enable lo device only if there were other net devices */
if (veths || privNet)
rc = virNetDevSetOnline("lo", true);
error_out:
VIR_FREE(newname);
return rc;
}
/*_syscall2(int, pivot_root, char *, newroot, const char *, oldroot)*/
extern int pivot_root(const char * new_root,const char * put_old);
static int lxcContainerChildMountSort(const void *a, const void *b)
{
const char **sa = (const char**)a;
const char **sb = (const char**)b;
/* Deliberately reversed args - we need to unmount deepest
children first */
return strcmp(*sb, *sa);
}
#ifndef MS_REC
# define MS_REC 16384
#endif
#ifndef MNT_DETACH
# define MNT_DETACH 0x00000002
#endif
#ifndef MS_PRIVATE
# define MS_PRIVATE (1<<18)
#endif
#ifndef MS_SLAVE
# define MS_SLAVE (1<<19)
#endif
static int lxcContainerGetSubtree(const char *prefix,
char ***mountsret,
size_t *nmountsret)
{
FILE *procmnt;
struct mntent mntent;
char mntbuf[1024];
int ret = -1;
char **mounts = NULL;
size_t nmounts = 0;
VIR_DEBUG("prefix=%s", prefix);
*mountsret = NULL;
*nmountsret = 0;
if (!(procmnt = setmntent("/proc/mounts", "r"))) {
virReportSystemError(errno, "%s",
_("Failed to read /proc/mounts"));
return -1;
}
while (getmntent_r(procmnt, &mntent, mntbuf, sizeof(mntbuf)) != NULL) {
VIR_DEBUG("Got %s", mntent.mnt_dir);
if (!STRPREFIX(mntent.mnt_dir, prefix))
continue;
if (VIR_REALLOC_N(mounts, nmounts+1) < 0)
goto cleanup;
if (VIR_STRDUP(mounts[nmounts], mntent.mnt_dir) < 0)
goto cleanup;
nmounts++;
VIR_DEBUG("Grabbed %s", mntent.mnt_dir);
}
if (mounts)
qsort(mounts, nmounts, sizeof(mounts[0]),
lxcContainerChildMountSort);
ret = 0;
cleanup:
*mountsret = mounts;
*nmountsret = nmounts;
endmntent(procmnt);
return ret;
}
static int lxcContainerUnmountSubtree(const char *prefix,
bool isOldRootFS)
{
char **mounts = NULL;
size_t nmounts = 0;
size_t i;
int saveErrno;
const char *failedUmount = NULL;
int ret = -1;
VIR_DEBUG("Unmount subtreee from %s", prefix);
if (lxcContainerGetSubtree(prefix, &mounts, &nmounts) < 0)
goto cleanup;
for (i = 0; i < nmounts; i++) {
VIR_DEBUG("Umount %s", mounts[i]);
if (umount(mounts[i]) < 0) {
char ebuf[1024];
failedUmount = mounts[i];
saveErrno = errno;
VIR_WARN("Failed to unmount '%s', trying to detach subtree '%s': %s",
failedUmount, mounts[nmounts-1],
virStrerror(errno, ebuf, sizeof(ebuf)));
break;
}
}
if (failedUmount) {
/* This detaches the subtree */
if (umount2(mounts[nmounts-1], MNT_DETACH) < 0) {
virReportSystemError(saveErrno,
_("Failed to unmount '%s' and could not detach subtree '%s'"),
failedUmount, mounts[nmounts-1]);
goto cleanup;
}
/* This unmounts the tmpfs on which the old root filesystem was hosted */
if (isOldRootFS &&
umount(mounts[nmounts-1]) < 0) {
virReportSystemError(saveErrno,
_("Failed to unmount '%s' and could not unmount old root '%s'"),
failedUmount, mounts[nmounts-1]);
goto cleanup;
}
}
ret = 0;
cleanup:
for (i = 0; i < nmounts; i++)
VIR_FREE(mounts[i]);
VIR_FREE(mounts);
return ret;
}
static int lxcContainerPrepareRoot(virDomainDefPtr def,
virDomainFSDefPtr root)
{
char *dst;
char *tmp;
if (root->type == VIR_DOMAIN_FS_TYPE_MOUNT)
return 0;
if (root->type == VIR_DOMAIN_FS_TYPE_FILE) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Unexpected root filesystem without loop device"));
return -1;
}
if (root->type != VIR_DOMAIN_FS_TYPE_BLOCK) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Unsupported root filesystem type %s"),
virDomainFSTypeToString(root->type));
return -1;
}
if (virAsprintf(&dst, "%s/%s.root",
LXC_STATE_DIR, def->name) < 0)
return -1;
tmp = root->dst;
root->dst = dst;
if (lxcContainerMountFSBlock(root, "") < 0) {
root->dst = tmp;
VIR_FREE(dst);
return -1;
}
root->dst = tmp;
root->type = VIR_DOMAIN_FS_TYPE_MOUNT;
VIR_FREE(root->src);
root->src = dst;
return 0;
}
static int lxcContainerPivotRoot(virDomainFSDefPtr root)
{
int ret;
char *oldroot = NULL, *newroot = NULL;
ret = -1;
VIR_DEBUG("Pivot via %s", root->src);
/* root->parent must be private, so make / private. */
if (mount("", "/", NULL, MS_PRIVATE|MS_REC, NULL) < 0) {
virReportSystemError(errno, "%s",
_("Failed to make root private"));
goto err;
}
if (virAsprintf(&oldroot, "%s/.oldroot", root->src) < 0)
goto err;
if (virFileMakePath(oldroot) < 0) {
virReportSystemError(errno,
_("Failed to create %s"),
oldroot);
goto err;
}
/* Create a tmpfs root since old and new roots must be
* on separate filesystems */
if (mount("tmprootfs", oldroot, "tmpfs", 0, NULL) < 0) {
virReportSystemError(errno,
_("Failed to mount empty tmpfs at %s"),
oldroot);
goto err;
}
/* Create a directory called 'new' in tmpfs */
if (virAsprintf(&newroot, "%s/new", oldroot) < 0)
goto err;
if (virFileMakePath(newroot) < 0) {
virReportSystemError(errno,
_("Failed to create %s"),
newroot);
goto err;
}
/* ... and mount our root onto it */
if (mount(root->src, newroot, NULL, MS_BIND|MS_REC, NULL) < 0) {
virReportSystemError(errno,
_("Failed to bind new root %s into tmpfs"),
root->src);
goto err;
}
if (root->readonly) {
if (mount(root->src, newroot, NULL, MS_BIND|MS_REC|MS_RDONLY|MS_REMOUNT, NULL) < 0) {
virReportSystemError(errno,
_("Failed to make new root %s readonly"),
root->src);
goto err;
}
}
/* Now we chdir into the tmpfs, then pivot into the
* root->src bind-mounted onto '/new' */
if (chdir(newroot) < 0) {
virReportSystemError(errno,
_("Failed to chdir into %s"), newroot);
goto err;
}
/* The old root directory will live at /.oldroot after
* this and will soon be unmounted completely */
if (pivot_root(".", ".oldroot") < 0) {
virReportSystemError(errno, "%s",
_("Failed to pivot root"));
goto err;
}
/* CWD is undefined after pivot_root, so go to / */
if (chdir("/") < 0)
goto err;
ret = 0;
err:
VIR_FREE(oldroot);
VIR_FREE(newroot);
return ret;
}
static int lxcContainerMountBasicFS(void)
{
const struct {
const char *src;
const char *dst;
const char *type;
const char *opts;
int mflags;
} mnts[] = {
/* When we want to make a bind mount readonly, for unknown reasons,
* it is currently necessary to bind it once, and then remount the
* bind with the readonly flag. If this is not done, then the original
* mount point in the main OS becomes readonly too which is not what
* we want. Hence some things have two entries here.
*/
{ "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV },
{ "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND },
{ "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY },
{ "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV },
{ "sysfs", "/sys", "sysfs", NULL, MS_BIND|MS_REMOUNT|MS_RDONLY },
#if WITH_SELINUX
{ SELINUX_MOUNT, SELINUX_MOUNT, "selinuxfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV },
{ SELINUX_MOUNT, SELINUX_MOUNT, NULL, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY },
#endif
};
size_t i;
int rc = -1;
VIR_DEBUG("Mounting basic filesystems");
for (i = 0; i < ARRAY_CARDINALITY(mnts); i++) {
const char *srcpath = NULL;
VIR_DEBUG("Processing %s -> %s",
mnts[i].src, mnts[i].dst);
srcpath = mnts[i].src;
/* Skip if mount doesn't exist in source */
if ((srcpath[0] == '/') &&
(access(srcpath, R_OK) < 0))
continue;
#if WITH_SELINUX
if (STREQ(mnts[i].src, SELINUX_MOUNT) &&
!is_selinux_enabled())
continue;
#endif
if (virFileMakePath(mnts[i].dst) < 0) {
virReportSystemError(errno,
_("Failed to mkdir %s"),
mnts[i].src);
goto cleanup;
}
VIR_DEBUG("Mount %s on %s type=%s flags=%x, opts=%s",
srcpath, mnts[i].dst, mnts[i].type, mnts[i].mflags, mnts[i].opts);
if (mount(srcpath, mnts[i].dst, mnts[i].type, mnts[i].mflags, mnts[i].opts) < 0) {
#if WITH_SELINUX
if (STREQ(mnts[i].src, SELINUX_MOUNT) &&
(errno == EINVAL || errno == EPERM))
continue;
#endif
virReportSystemError(errno,
_("Failed to mount %s on %s type %s flags=%x opts=%s"),
srcpath, mnts[i].dst, NULLSTR(mnts[i].type),
mnts[i].mflags, NULLSTR(mnts[i].opts));
goto cleanup;
}
}
rc = 0;
cleanup:
VIR_DEBUG("rc=%d", rc);
return rc;
}
#if WITH_FUSE
static int lxcContainerMountProcFuse(virDomainDefPtr def,
const char *stateDir)
{
int ret;
char *meminfo_path = NULL;
VIR_DEBUG("Mount /proc/meminfo stateDir=%s", stateDir);
if ((ret = virAsprintf(&meminfo_path,
"/.oldroot/%s/%s.fuse/meminfo",
stateDir,
def->name)) < 0)
return ret;
if ((ret = mount(meminfo_path, "/proc/meminfo",
NULL, MS_BIND, NULL)) < 0) {
virReportSystemError(errno,
_("Failed to mount %s on /proc/meminfo"),
meminfo_path);
}
VIR_FREE(meminfo_path);
return ret;
}
#else
static int lxcContainerMountProcFuse(virDomainDefPtr def ATTRIBUTE_UNUSED,
const char *stateDir ATTRIBUTE_UNUSED)
{
return 0;
}
#endif
static int lxcContainerMountFSDev(virDomainDefPtr def,
const char *stateDir)
{
int ret;
char *path = NULL;
VIR_DEBUG("Mount /dev/ stateDir=%s", stateDir);
if ((ret = virAsprintf(&path, "/.oldroot/%s/%s.dev",
stateDir, def->name)) < 0)
return ret;
VIR_DEBUG("Tring to move %s to /dev", path);
if ((ret = mount(path, "/dev", NULL, MS_MOVE, NULL)) < 0) {
virReportSystemError(errno,
_("Failed to mount %s on /dev"),
path);
}
VIR_FREE(path);
return ret;
}
static int lxcContainerMountFSDevPTS(virDomainDefPtr def,
const char *stateDir)
{
int ret;
char *path = NULL;
VIR_DEBUG("Mount /dev/pts stateDir=%s", stateDir);
if ((ret = virAsprintf(&path,
"/.oldroot/%s/%s.devpts",
stateDir,
def->name)) < 0)
return ret;
if (virFileMakePath("/dev/pts") < 0) {
virReportSystemError(errno, "%s",
_("Cannot create /dev/pts"));
goto cleanup;
}
VIR_DEBUG("Trying to move %s to /dev/pts", path);
if ((ret = mount(path, "/dev/pts",
NULL, MS_MOVE, NULL)) < 0) {
virReportSystemError(errno,
_("Failed to mount %s on /dev/pts"),
path);
goto cleanup;
}
cleanup:
VIR_FREE(path);
return ret;
}
static int lxcContainerSetupDevices(char **ttyPaths, size_t nttyPaths)
{
size_t i;
const struct {
const char *src;
const char *dst;
} links[] = {
{ "/proc/self/fd/0", "/dev/stdin" },
{ "/proc/self/fd/1", "/dev/stdout" },
{ "/proc/self/fd/2", "/dev/stderr" },
{ "/proc/self/fd", "/dev/fd" },
};
for (i = 0; i < ARRAY_CARDINALITY(links); i++) {
if (symlink(links[i].src, links[i].dst) < 0) {
virReportSystemError(errno,
_("Failed to symlink device %s to %s"),
links[i].dst, links[i].src);
return -1;
}
}
/* We have private devpts capability, so bind that */
if (virFileTouch("/dev/ptmx", 0666) < 0)
return -1;
if (mount("/dev/pts/ptmx", "/dev/ptmx", "ptmx", MS_BIND, NULL) < 0) {
virReportSystemError(errno, "%s",
_("Failed to bind /dev/pts/ptmx on to /dev/ptmx"));
return -1;
}
for (i = 0; i < nttyPaths; i++) {
char *tty;
if (virAsprintf(&tty, "/dev/tty%zu", i+1) < 0)
return -1;
if (symlink(ttyPaths[i], tty) < 0) {
VIR_FREE(tty);
virReportSystemError(errno,
_("Failed to symlink %s to %s"),
ttyPaths[i], tty);
return -1;
}
VIR_FREE(tty);
if (i == 0 &&
symlink(ttyPaths[i], "/dev/console") < 0) {
virReportSystemError(errno,
_("Failed to symlink %s to /dev/console"),
ttyPaths[i]);
return -1;
}
}
return 0;
}
static int lxcContainerMountFSBind(virDomainFSDefPtr fs,
const char *srcprefix)
{
char *src = NULL;
int ret = -1;
struct stat st;
if (virAsprintf(&src, "%s%s", srcprefix, fs->src) < 0)
goto cleanup;
if (stat(fs->dst, &st) < 0) {
if (errno != ENOENT) {
virReportSystemError(errno, _("Unable to stat bind target %s"),
fs->dst);
goto cleanup;
}
/* ENOENT => create the target dir or file */
if (stat(src, &st) < 0) {
virReportSystemError(errno, _("Unable to stat bind source %s"),
src);
goto cleanup;
}
if (S_ISDIR(st.st_mode)) {
if (virFileMakePath(fs->dst) < 0) {
virReportSystemError(errno,
_("Failed to create %s"),
fs->dst);
goto cleanup;
}
} else {
/* Create Empty file for target mount point */
int fd = open(fs->dst, O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666);
if (fd < 0) {
if (errno != EEXIST) {
virReportSystemError(errno,
_("Failed to create bind target %s"),
fs->dst);
goto cleanup;
}
}
if (VIR_CLOSE(fd) < 0) {
virReportSystemError(errno,
_("Failed to close bind target %s"),
fs->dst);
goto cleanup;
}
}
}
if (mount(src, fs->dst, NULL, MS_BIND, NULL) < 0) {
virReportSystemError(errno,
_("Failed to bind mount directory %s to %s"),
src, fs->dst);
goto cleanup;
}
if (fs->readonly) {
VIR_DEBUG("Binding %s readonly", fs->dst);
if (mount(src, fs->dst, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0) {
virReportSystemError(errno,
_("Failed to make directory %s readonly"),
fs->dst);
}
}
ret = 0;
cleanup:
VIR_FREE(src);
return ret;
}
#ifdef WITH_BLKID
static int
lxcContainerMountDetectFilesystem(const char *src, char **type)
{
int fd;
int ret = -1;
int rc;
const char *data = NULL;
blkid_probe blkid = NULL;
*type = NULL;
if ((fd = open(src, O_RDONLY)) < 0) {
virReportSystemError(errno,
_("Unable to open filesystem %s"), src);
return -1;
}
if (!(blkid = blkid_new_probe())) {
virReportSystemError(errno, "%s",
_("Unable to create blkid library handle"));
goto cleanup;
}
if (blkid_probe_set_device(blkid, fd, 0, 0) < 0) {
virReportSystemError(EINVAL,
_("Unable to associate device %s with blkid library"),
src);
goto cleanup;
}
blkid_probe_enable_superblocks(blkid, 1);
blkid_probe_set_superblocks_flags(blkid, BLKID_SUBLKS_TYPE);
rc = blkid_do_safeprobe(blkid);
if (rc != 0) {
if (rc == 1) /* Nothing found, return success with *type == NULL */
goto done;
if (rc == -2) {
virReportSystemError(EINVAL,
_("Too many filesystems detected for %s"),
src);
} else {
virReportSystemError(errno,
_("Unable to detect filesystem for %s"),
src);
}
goto cleanup;
}
if (blkid_probe_lookup_value(blkid, "TYPE", &data, NULL) < 0) {
virReportSystemError(ENOENT,
_("Unable to find filesystem type for %s"),
src);
goto cleanup;
}
if (VIR_STRDUP(*type, data) < 0)
goto cleanup;
done:
ret = 0;
cleanup:
VIR_FORCE_CLOSE(fd);
if (blkid)
blkid_free_probe(blkid);
return ret;
}
#else /* ! WITH_BLKID */
static int
lxcContainerMountDetectFilesystem(const char *src ATTRIBUTE_UNUSED,
char **type)
{
/* No libblkid, so just return success with no detected type */
*type = NULL;
return 0;
}
#endif /* ! WITH_BLKID */
/*
* This functions attempts to do automatic detection of filesystem
* type following the same rules as the util-linux 'mount' binary.
*
* The main difference is that we don't (currently) try to use
* libblkid to detect the format first. We go straight to using
* /etc/filesystems, and then /proc/filesystems
*/
static int lxcContainerMountFSBlockAuto(virDomainFSDefPtr fs,
int fsflags,
const char *src)
{
FILE *fp = NULL;
int ret = -1;
bool tryProc = false;
bool gotStar = false;
char *fslist = NULL;
char *line = NULL;
const char *type;
VIR_DEBUG("src=%s dst=%s", src, fs->dst);
/* First time around we use /etc/filesystems */
retry:
if (virAsprintf(&fslist, "/.oldroot%s",
tryProc ? "/proc/filesystems" : "/etc/filesystems") < 0)
goto cleanup;
VIR_DEBUG("Open fslist %s", fslist);
if (!(fp = fopen(fslist, "r"))) {
/* If /etc/filesystems does not exist, then we need to retry
* with /proc/filesystems next
*/
if (errno == ENOENT &&
!tryProc) {
tryProc = true;
VIR_FREE(fslist);
goto retry;
}
virReportSystemError(errno,
_("Unable to read %s"),
fslist);
goto cleanup;
}
while (!feof(fp)) {
size_t n;
VIR_FREE(line);
if (getline(&line, &n, fp) <= 0) {
if (feof(fp))
break;
goto cleanup;
}
if (strstr(line, "nodev"))
continue;
type = strchr(line, '\n');
if (type)
line[type-line] = '\0';
type = line;
virSkipSpaces(&type);
/*
* /etc/filesystems is only allowed to contain '*' on the last line
*/
if (gotStar && !tryProc) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("%s has unexpected '*' before last line"),
fslist);
goto cleanup;
}
/* An '*' on the last line in /etc/filesystems
* means try /proc/filesystems next. We don't
* jump immediately though, since we need to see
* if any more lines follow
*/
if (!tryProc &&
STREQ(type, "*"))
gotStar = true;
VIR_DEBUG("Trying mount %s with %s", src, type);
if (mount(src, fs->dst, type, fsflags, NULL) < 0) {
/* These errnos indicate a bogus filesystem type for
* the image we have, so skip to the next type
*/
if (errno == EINVAL || errno == ENODEV)
continue;
virReportSystemError(errno,
_("Failed to mount device %s to %s"),
src, fs->dst);
goto cleanup;
}
ret = 0;
break;
}
/* We've got to the end of /etc/filesystems and saw
* a '*', so we must try /proc/filesystems next
*/
if (ret != 0 &&
!tryProc &&
gotStar) {
tryProc = true;
VIR_FREE(fslist);
VIR_FORCE_FCLOSE(fp);
goto retry;
}
if (ret != 0) {
virReportSystemError(ENODEV,
_("Failed to mount device %s to %s, unable to detect filesystem"),
src, fs->dst);
}
VIR_DEBUG("Done mounting filesystem ret=%d tryProc=%d", ret, tryProc);
cleanup:
VIR_FREE(line);
VIR_FREE(fslist);
VIR_FORCE_FCLOSE(fp);
return ret;
}
/*
* Mount a block device 'src' on fs->dst, automatically
* probing for filesystem type
*/
static int lxcContainerMountFSBlockHelper(virDomainFSDefPtr fs,
const char *src)
{
int fsflags = 0;
int ret = -1;
char *format = NULL;
if (fs->readonly)
fsflags |= MS_RDONLY;
if (virFileMakePath(fs->dst) < 0) {
virReportSystemError(errno,
_("Failed to create %s"),
fs->dst);
goto cleanup;
}
if (lxcContainerMountDetectFilesystem(src, &format) < 0)
goto cleanup;
if (format) {
VIR_DEBUG("Mount %s with detected format %s", src, format);
if (mount(src, fs->dst, format, fsflags, NULL) < 0) {
virReportSystemError(errno,
_("Failed to mount device %s to %s as %s"),
src, fs->dst, format);
goto cleanup;
}
ret = 0;
} else {
ret = lxcContainerMountFSBlockAuto(fs, fsflags, src);
}
cleanup:
VIR_FREE(format);
return ret;
}
static int lxcContainerMountFSBlock(virDomainFSDefPtr fs,
const char *srcprefix)
{
char *src = NULL;
int ret = -1;
if (virAsprintf(&src, "%s%s", srcprefix, fs->src) < 0)
goto cleanup;
ret = lxcContainerMountFSBlockHelper(fs, src);
VIR_DEBUG("Done mounting filesystem ret=%d", ret);
cleanup:
VIR_FREE(src);
return ret;
}
static int lxcContainerMountFSTmpfs(virDomainFSDefPtr fs,
char *sec_mount_options)
{
int ret = -1;
char *data = NULL;
if (virAsprintf(&data,
"size=%lldk%s", fs->usage, sec_mount_options) < 0)
goto cleanup;
if (virFileMakePath(fs->dst) < 0) {
virReportSystemError(errno,
_("Failed to create %s"),
fs->dst);
goto cleanup;
}
if (mount("tmpfs", fs->dst, "tmpfs", MS_NOSUID|MS_NODEV, data) < 0) {
virReportSystemError(errno,
_("Failed to mount directory %s as tmpfs"),
fs->dst);
goto cleanup;
}
if (fs->readonly) {
VIR_DEBUG("Binding %s readonly", fs->dst);
if (mount(fs->dst, fs->dst, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0) {
virReportSystemError(errno,
_("Failed to make directory %s readonly"),
fs->dst);
}
}
ret = 0;
cleanup:
VIR_FREE(data);
return ret;
}
static int lxcContainerMountFS(virDomainFSDefPtr fs,
char *sec_mount_options)
{
switch (fs->type) {
case VIR_DOMAIN_FS_TYPE_MOUNT:
if (lxcContainerMountFSBind(fs, "/.oldroot") < 0)
return -1;
break;
case VIR_DOMAIN_FS_TYPE_BLOCK:
if (lxcContainerMountFSBlock(fs, "/.oldroot") < 0)
return -1;
break;
case VIR_DOMAIN_FS_TYPE_RAM:
if (lxcContainerMountFSTmpfs(fs, sec_mount_options) < 0)
return -1;
break;
case VIR_DOMAIN_FS_TYPE_BIND:
if (lxcContainerMountFSBind(fs, "") < 0)
return -1;
break;
case VIR_DOMAIN_FS_TYPE_FILE:
/* We do actually support this, but the lxc controller
* should have associated the file with a loopback
* device and changed this to TYPE_BLOCK for us */
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Unexpected filesystem type %s"),
virDomainFSTypeToString(fs->type));
break;
default:
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Cannot mount filesystem type %s"),
virDomainFSTypeToString(fs->type));
break;
}
return 0;
}
static int lxcContainerMountAllFS(virDomainDefPtr vmDef,
char *sec_mount_options)
{
size_t i;
VIR_DEBUG("Mounting all non-root filesystems");
/* Pull in rest of container's mounts */
for (i = 0; i < vmDef->nfss; i++) {
if (STREQ(vmDef->fss[i]->dst, "/"))
continue;
if (lxcContainerUnmountSubtree(vmDef->fss[i]->dst,
false) < 0)
return -1;
if (lxcContainerMountFS(vmDef->fss[i], sec_mount_options) < 0)
return -1;
}
VIR_DEBUG("Mounted all non-root filesystems");
return 0;
}
static int lxcContainerSetupDisk(virDomainDefPtr vmDef,
virDomainDiskDefPtr def,
virSecurityManagerPtr securityDriver)
{
char *src = NULL;
char *dst = NULL;
int ret = -1;
struct stat sb;
mode_t mode;
char *tmpsrc = def->src;
if (def->type != VIR_DOMAIN_DISK_TYPE_BLOCK) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("Can't setup disk for non-block device"));
goto cleanup;
}
if (def->src == NULL) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("Can't setup disk without media"));
goto cleanup;
}
if (virAsprintf(&src, "/.oldroot/%s", def->src) < 0)
goto cleanup;
if (virAsprintf(&dst, "/dev/%s", def->dst) < 0)
goto cleanup;
if (stat(src, &sb) < 0) {
virReportSystemError(errno,
_("Unable to access %s"), def->src);
goto cleanup;
}
if (!S_ISCHR(sb.st_mode) && !S_ISBLK(sb.st_mode)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Disk source %s must be a character/block device"),
def->src);
goto cleanup;
}
mode = 0700;
if (S_ISCHR(sb.st_mode))
mode |= S_IFCHR;
else
mode |= S_IFBLK;
/* Yes, the device name we're creating may not
* actually correspond to the major:minor number
* we're using, but we've no other option at this
* time. Just have to hope that containerized apps
* don't get upset that the major:minor is different
* to that normally implied by the device name
*/
VIR_DEBUG("Creating dev %s (%d,%d) from %s",
dst, major(sb.st_rdev), minor(sb.st_rdev), src);
if (mknod(dst, mode, sb.st_rdev) < 0) {
virReportSystemError(errno,
_("Unable to create device %s"),
dst);
goto cleanup;
}
/* Labelling normally operates on src, but we need
* to actally label the dst here, so hack the config */
def->src = dst;
if (virSecurityManagerSetImageLabel(securityDriver, vmDef, def) < 0)
goto cleanup;
ret = 0;
cleanup:
def->src = tmpsrc;
VIR_FREE(src);
VIR_FREE(dst);
return ret;
}
static int lxcContainerSetupAllDisks(virDomainDefPtr vmDef,
virSecurityManagerPtr securityDriver)
{
size_t i;
VIR_DEBUG("Setting up disks");
for (i = 0; i < vmDef->ndisks; i++) {
if (lxcContainerSetupDisk(vmDef, vmDef->disks[i],
securityDriver) < 0)
return -1;
}
VIR_DEBUG("Setup all disks");
return 0;
}
static int lxcContainerSetupHostdevSubsysUSB(virDomainDefPtr vmDef ATTRIBUTE_UNUSED,
virDomainHostdevDefPtr def ATTRIBUTE_UNUSED,
virSecurityManagerPtr securityDriver ATTRIBUTE_UNUSED)
{
int ret = -1;
char *src = NULL;
char *dstdir = NULL;
char *dstfile = NULL;
struct stat sb;
mode_t mode;
if (virAsprintf(&dstdir, USB_DEVFS "/%03d",
def->source.subsys.u.usb.bus) < 0)
goto cleanup;
if (virAsprintf(&dstfile, "%s/%03d",
dstdir,
def->source.subsys.u.usb.device) < 0)
goto cleanup;
if (virAsprintf(&src, "/.oldroot/%s", dstfile) < 0)
goto cleanup;
if (stat(src, &sb) < 0) {
virReportSystemError(errno,
_("Unable to access %s"), src);
goto cleanup;
}
if (!S_ISCHR(sb.st_mode)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("USB source %s was not a character device"),
src);
goto cleanup;
}
mode = 0700 | S_IFCHR;
if (virFileMakePath(dstdir) < 0) {
virReportSystemError(errno,
_("Unable to create %s"), dstdir);
goto cleanup;
}
VIR_DEBUG("Creating dev %s (%d,%d)",
dstfile, major(sb.st_rdev), minor(sb.st_rdev));
if (mknod(dstfile, mode, sb.st_rdev) < 0) {
virReportSystemError(errno,
_("Unable to create device %s"),
dstfile);
goto cleanup;
}
if (virSecurityManagerSetHostdevLabel(securityDriver, vmDef, def, NULL) < 0)
goto cleanup;
ret = 0;
cleanup:
VIR_FREE(src);
VIR_FREE(dstfile);
VIR_FREE(dstdir);
return ret;
}
int lxcContainerSetupHostdevCapsMakePath(const char *dev)
{
int ret = -1;
char *dir, *tmp;
if (VIR_STRDUP(dir, dev) < 0)
return -1;
if ((tmp = strrchr(dir, '/'))) {
*tmp = '\0';
if (virFileMakePath(dir) < 0) {
virReportSystemError(errno,
_("Failed to create directory for '%s' dev '%s'"),
dir, dev);
goto cleanup;
}
}
ret = 0;
cleanup:
VIR_FREE(dir);
return ret;
}
static int lxcContainerSetupHostdevCapsStorage(virDomainDefPtr vmDef ATTRIBUTE_UNUSED,
virDomainHostdevDefPtr def ATTRIBUTE_UNUSED,
virSecurityManagerPtr securityDriver ATTRIBUTE_UNUSED)
{
char *src = NULL;
int ret = -1;
struct stat sb;
mode_t mode;
char *dev = def->source.caps.u.storage.block;
if (dev == NULL) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("Missing storage host block path"));
goto cleanup;
}
if (virAsprintf(&src, "/.oldroot/%s", dev) < 0)
goto cleanup;
if (stat(src, &sb) < 0) {
virReportSystemError(errno,
_("Unable to access %s"),
src);
goto cleanup;
}
if (!S_ISBLK(sb.st_mode)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Storage source %s must be a block device"),
dev);
goto cleanup;
}
if (lxcContainerSetupHostdevCapsMakePath(dev) < 0) {
virReportError(errno,
_("Failed to create directory for device %s"),
dev);
goto cleanup;
}
mode = 0700 | S_IFBLK;
VIR_DEBUG("Creating dev %s (%d,%d)", dev,
major(sb.st_rdev), minor(sb.st_rdev));
if (mknod(dev, mode, sb.st_rdev) < 0) {
virReportSystemError(errno,
_("Unable to create device %s"),
dev);
goto cleanup;
}
if (virSecurityManagerSetHostdevLabel(securityDriver, vmDef, def, NULL) < 0)
goto cleanup;
ret = 0;
cleanup:
VIR_FREE(src);
return ret;
}
static int lxcContainerSetupHostdevCapsMisc(virDomainDefPtr vmDef ATTRIBUTE_UNUSED,
virDomainHostdevDefPtr def ATTRIBUTE_UNUSED,
virSecurityManagerPtr securityDriver ATTRIBUTE_UNUSED)
{
char *src = NULL;
int ret = -1;
struct stat sb;
mode_t mode;
char *dev = def->source.caps.u.misc.chardev;
if (dev == NULL) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("Missing storage host block path"));
goto cleanup;
}
if (virAsprintf(&src, "/.oldroot/%s", dev) < 0)
goto cleanup;
if (stat(src, &sb) < 0) {
virReportSystemError(errno,
_("Unable to access %s"),
src);
goto cleanup;
}
if (!S_ISCHR(sb.st_mode)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Storage source %s must be a character device"),
dev);
goto cleanup;
}
if (lxcContainerSetupHostdevCapsMakePath(dev) < 0) {
virReportError(errno,
_("Failed to create directory for device %s"),
dev);
goto cleanup;
}
mode = 0700 | S_IFCHR;
VIR_DEBUG("Creating dev %s (%d,%d)", dev,
major(sb.st_rdev), minor(sb.st_rdev));
if (mknod(dev, mode, sb.st_rdev) < 0) {
virReportSystemError(errno,
_("Unable to create device %s"),
dev);
goto cleanup;
}
if (virSecurityManagerSetHostdevLabel(securityDriver, vmDef, def, NULL) < 0)
goto cleanup;
ret = 0;
cleanup:
VIR_FREE(src);
return ret;
}
static int lxcContainerSetupHostdevSubsys(virDomainDefPtr vmDef,
virDomainHostdevDefPtr def,
virSecurityManagerPtr securityDriver)
{
switch (def->source.subsys.type) {
case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB:
return lxcContainerSetupHostdevSubsysUSB(vmDef, def, securityDriver);
default:
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Unsupported host device mode %s"),
virDomainHostdevSubsysTypeToString(def->source.subsys.type));
return -1;
}
}
static int lxcContainerSetupHostdevCaps(virDomainDefPtr vmDef,
virDomainHostdevDefPtr def,
virSecurityManagerPtr securityDriver)
{
switch (def->source.subsys.type) {
case VIR_DOMAIN_HOSTDEV_CAPS_TYPE_STORAGE:
return lxcContainerSetupHostdevCapsStorage(vmDef, def, securityDriver);
case VIR_DOMAIN_HOSTDEV_CAPS_TYPE_MISC:
return lxcContainerSetupHostdevCapsMisc(vmDef, def, securityDriver);
case VIR_DOMAIN_HOSTDEV_CAPS_TYPE_NET:
return 0; // case is handled in virLXCControllerMoveInterfaces
default:
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Unsupported host device mode %s"),
virDomainHostdevCapsTypeToString(def->source.subsys.type));
return -1;
}
}
static int lxcContainerSetupAllHostdevs(virDomainDefPtr vmDef,
virSecurityManagerPtr securityDriver)
{
size_t i;
VIR_DEBUG("Setting up hostdevs");
for (i = 0; i < vmDef->nhostdevs; i++) {
virDomainHostdevDefPtr def = vmDef->hostdevs[i];
switch (def->mode) {
case VIR_DOMAIN_HOSTDEV_MODE_SUBSYS:
if (lxcContainerSetupHostdevSubsys(vmDef, def, securityDriver) < 0)
return -1;
break;
case VIR_DOMAIN_HOSTDEV_MODE_CAPABILITIES:
if (lxcContainerSetupHostdevCaps(vmDef, def, securityDriver) < 0)
return -1;
break;
default:
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Unsupported host device mode %s"),
virDomainHostdevModeTypeToString(def->mode));
return -1;
}
}
VIR_DEBUG("Setup all hostdevs");
return 0;
}
/* Got a FS mapped to /, we're going the pivot_root
* approach to do a better-chroot-than-chroot
* this is based on this thread http://lkml.org/lkml/2008/3/5/29
*/
static int lxcContainerSetupPivotRoot(virDomainDefPtr vmDef,
virDomainFSDefPtr root,
char **ttyPaths,
size_t nttyPaths,
virSecurityManagerPtr securityDriver)
{
virCgroupPtr cgroup = NULL;
int rc;
int ret = -1;
char *sec_mount_options;
char *stateDir = NULL;
if (!(sec_mount_options = virSecurityManagerGetMountOptions(securityDriver, vmDef)))
return -1;
/* Before pivoting we need to identify any
* cgroups controllers that are mounted */
if ((rc = virCgroupNewSelf(&cgroup)) != 0) {
virReportSystemError(-rc, "%s",
_("Cannot identify cgroup placement"));
goto cleanup;
}
if (virFileResolveAllLinks(LXC_STATE_DIR, &stateDir) < 0)
goto cleanup;
/* Ensure the root filesystem is mounted */
if (lxcContainerPrepareRoot(vmDef, root) < 0)
goto cleanup;
/* Gives us a private root, leaving all parent OS mounts on /.oldroot */
if (lxcContainerPivotRoot(root) < 0)
goto cleanup;
#if WITH_SELINUX
/* Some versions of Linux kernel don't let you overmount
* the selinux filesystem, so make sure we kill it first
*/
/* Filed coverity bug for false positive 'USE_AFTER_FREE' due to swap
* of root->src with root->dst and the VIR_FREE(root->src) prior to the
* reset of root->src in lxcContainerPrepareRoot()
*/
/* coverity[deref_arg] */
if (STREQ(root->src, "/") &&
lxcContainerUnmountSubtree(SELINUX_MOUNT, false) < 0)
goto cleanup;
#endif
/* If we have the root source being '/', then we need to
* get rid of any existing stuff under /proc, /sys & /tmp.
* We need new namespace aware versions of those. We must
* do /proc last otherwise we won't find /proc/mounts :-) */
if (STREQ(root->src, "/") &&
(lxcContainerUnmountSubtree("/sys", false) < 0 ||
lxcContainerUnmountSubtree("/dev", false) < 0 ||
lxcContainerUnmountSubtree("/proc", false) < 0))
goto cleanup;
/* Mounts the core /proc, /sys, etc filesystems */
if (lxcContainerMountBasicFS() < 0)
goto cleanup;
/* Mounts /proc/meminfo etc sysinfo */
if (lxcContainerMountProcFuse(vmDef, stateDir) < 0)
goto cleanup;
/* Now we can re-mount the cgroups controllers in the
* same configuration as before */
if (virCgroupIsolateMount(cgroup, "/.oldroot/", sec_mount_options) < 0)
goto cleanup;
/* Mounts /dev */
if (lxcContainerMountFSDev(vmDef, stateDir) < 0)
goto cleanup;
/* Mounts /dev/pts */
if (lxcContainerMountFSDevPTS(vmDef, stateDir) < 0)
goto cleanup;
/* Setup device nodes in /dev/ */
if (lxcContainerSetupDevices(ttyPaths, nttyPaths) < 0)
goto cleanup;
/* Sets up any non-root mounts from guest config */
if (lxcContainerMountAllFS(vmDef, sec_mount_options) < 0)
goto cleanup;
/* Sets up any extra disks from guest config */
if (lxcContainerSetupAllDisks(vmDef, securityDriver) < 0)
goto cleanup;
/* Sets up any extra host devices from guest config */
if (lxcContainerSetupAllHostdevs(vmDef, securityDriver) < 0)
goto cleanup;
/* Gets rid of all remaining mounts from host OS, including /.oldroot itself */
if (lxcContainerUnmountSubtree("/.oldroot", true) < 0)
goto cleanup;
ret = 0;
cleanup:
VIR_FREE(stateDir);
virCgroupFree(&cgroup);
VIR_FREE(sec_mount_options);
return ret;
}
static int lxcContainerResolveSymlinks(virDomainDefPtr vmDef)
{
char *newroot;
size_t i;
for (i = 0; i < vmDef->nfss; i++) {
virDomainFSDefPtr fs = vmDef->fss[i];
if (!fs->src)
continue;
if (virFileResolveAllLinks(fs->src, &newroot) < 0)
return -1;
VIR_DEBUG("Resolved '%s' to %s", fs->src, newroot);
VIR_FREE(fs->src);
fs->src = newroot;
}
return 0;
}
/*
* This is running as the 'init' process insid the container.
* It removes some capabilities that could be dangerous to
* host system, since they are not currently "containerized"
*/
static int lxcContainerDropCapabilities(bool keepReboot ATTRIBUTE_UNUSED)
{
#if WITH_CAPNG
int ret;
capng_get_caps_process();
if ((ret = capng_updatev(CAPNG_DROP,
CAPNG_EFFECTIVE | CAPNG_PERMITTED |
CAPNG_INHERITABLE | CAPNG_BOUNDING_SET,
CAP_SYS_MODULE, /* No kernel module loading */
CAP_SYS_TIME, /* No changing the clock */
CAP_MKNOD, /* No creating device nodes */
CAP_AUDIT_CONTROL, /* No messing with auditing status */
CAP_MAC_ADMIN, /* No messing with LSM config */
keepReboot ? -1 : CAP_SYS_BOOT, /* No use of reboot */
-1)) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Failed to remove capabilities: %d"), ret);
return -1;
}
if ((ret = capng_apply(CAPNG_SELECT_BOTH)) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Failed to apply capabilities: %d"), ret);
return -1;
}
/* We do not need to call capng_lock() in this case. The bounding
* set restriction will prevent them reacquiring sys_boot/module/time,
* etc which is all that matters for the container. Once inside the
* container it is fine for SECURE_NOROOT / SECURE_NO_SETUID_FIXUP to
* be unmasked - they can never escape the bounding set. */
#else
VIR_WARN("libcap-ng support not compiled in, unable to clear capabilities");
#endif
return 0;
}
/**
* lxcContainerChild:
* @data: pointer to container arguments
*
* This function is run in the process clone()'d in lxcStartContainer.
* Perform a number of container setup tasks:
* Setup container file system
* mount container /proca
* Then exec's the container init
*
* Returns 0 on success or -1 in case of error
*/
static int lxcContainerChild(void *data)
{
lxc_child_argv_t *argv = data;
virDomainDefPtr vmDef = argv->config;
int ttyfd = -1;
int ret = -1;
char *ttyPath = NULL;
virDomainFSDefPtr root;
virCommandPtr cmd = NULL;
int hasReboot;
if (NULL == vmDef) {
virReportError(VIR_ERR_INTERNAL_ERROR,
"%s", _("lxcChild() passed invalid vm definition"));
goto cleanup;
}
/* Wait for controller to finish setup tasks, including
* things like move of network interfaces, uid/gid mapping
*/
if (lxcContainerWaitForContinue(argv->monitor) < 0) {
virReportSystemError(errno, "%s",
_("Failed to read the container continue message"));
goto cleanup;
}
VIR_DEBUG("Received container continue message");
if ((hasReboot = lxcContainerHasReboot()) < 0)
goto cleanup;
cmd = lxcContainerBuildInitCmd(vmDef);
virCommandWriteArgLog(cmd, 1);
if (lxcContainerSetID(vmDef) < 0)
goto cleanup;
root = virDomainGetRootFilesystem(vmDef);
if (argv->nttyPaths) {
const char *tty = argv->ttyPaths[0];
if (STRPREFIX(tty, "/dev/pts/"))
tty += strlen("/dev/pts/");
if (virAsprintf(&ttyPath, "%s/%s.devpts/%s",
LXC_STATE_DIR, vmDef->name, tty) < 0)
goto cleanup;
} else if (VIR_STRDUP(ttyPath, "/dev/null") < 0) {
goto cleanup;
}
VIR_DEBUG("Container TTY path: %s", ttyPath);
ttyfd = open(ttyPath, O_RDWR|O_NOCTTY);
if (ttyfd < 0) {
virReportSystemError(errno,
_("Failed to open tty %s"),
ttyPath);
goto cleanup;
}
if (lxcContainerResolveSymlinks(vmDef) < 0)
goto cleanup;
if (lxcContainerSetupPivotRoot(vmDef, root,
argv->ttyPaths, argv->nttyPaths,
argv->securityDriver) < 0)
goto cleanup;
if (!virFileExists(vmDef->os.init)) {
virReportSystemError(errno,
_("cannot find init path '%s' relative to container root"),
vmDef->os.init);
goto cleanup;
}
/* rename and enable interfaces */
if (lxcContainerRenameAndEnableInterfaces(!!(vmDef->features &
(1 << VIR_DOMAIN_FEATURE_PRIVNET)),
argv->nveths,
argv->veths) < 0) {
goto cleanup;
}
/* drop a set of root capabilities */
if (lxcContainerDropCapabilities(!!hasReboot) < 0)
goto cleanup;
if (lxcContainerSendContinue(argv->handshakefd) < 0) {
virReportSystemError(errno, "%s",
_("failed to send continue signal to controller"));
goto cleanup;
}
VIR_DEBUG("Setting up security labeling");
if (virSecurityManagerSetProcessLabel(argv->securityDriver, vmDef) < 0)
goto cleanup;
if (lxcContainerSetStdio(argv->monitor, ttyfd, argv->handshakefd) < 0) {
goto cleanup;
}
ret = 0;
cleanup:
VIR_FREE(ttyPath);
VIR_FORCE_CLOSE(ttyfd);
VIR_FORCE_CLOSE(argv->monitor);
VIR_FORCE_CLOSE(argv->handshakefd);
if (ret == 0) {
/* this function will only return if an error occurred */
ret = virCommandExec(cmd);
}
virCommandFree(cmd);
return ret;
}
static int userns_supported(void)
{
return lxcContainerAvailable(LXC_CONTAINER_FEATURE_USER) == 0;
}
static int userns_required(virDomainDefPtr def)
{
return def->idmap.uidmap && def->idmap.gidmap;
}
virArch lxcContainerGetAlt32bitArch(virArch arch)
{
/* Any Linux 64bit arch which has a 32bit
* personality available should be listed here */
if (arch == VIR_ARCH_X86_64)
return VIR_ARCH_I686;
if (arch == VIR_ARCH_S390X)
return VIR_ARCH_S390;
if (arch == VIR_ARCH_PPC64)
return VIR_ARCH_PPC;
if (arch == VIR_ARCH_PARISC64)
return VIR_ARCH_PARISC;
if (arch == VIR_ARCH_SPARC64)
return VIR_ARCH_SPARC;
if (arch == VIR_ARCH_MIPS64)
return VIR_ARCH_MIPS;
if (arch == VIR_ARCH_MIPS64EL)
return VIR_ARCH_MIPSEL;
return VIR_ARCH_NONE;
}
static bool
lxcNeedNetworkNamespace(virDomainDefPtr def)
{
size_t i;
if (def->nets != NULL)
return true;
if (def->features & (1 << VIR_DOMAIN_FEATURE_PRIVNET))
return true;
for (i = 0; i < def->nhostdevs; i++) {
if (def->hostdevs[i]->mode == VIR_DOMAIN_HOSTDEV_MODE_CAPABILITIES &&
def->hostdevs[i]->source.caps.type == VIR_DOMAIN_HOSTDEV_CAPS_TYPE_NET)
return true;
}
return false;
}
/**
* lxcContainerStart:
* @def: pointer to virtual machine structure
* @nveths: number of interfaces
* @veths: interface names
* @control: control FD to the container
* @ttyPath: path of tty to set as the container console
*
* Starts a container process by calling clone() with the namespace flags
*
* Returns PID of container on success or -1 in case of error
*/
int lxcContainerStart(virDomainDefPtr def,
virSecurityManagerPtr securityDriver,
size_t nveths,
char **veths,
int control,
int handshakefd,
char **ttyPaths,
size_t nttyPaths)
{
pid_t pid;
int cflags;
int stacksize = getpagesize() * 4;
char *stack, *stacktop;
lxc_child_argv_t args = { def, securityDriver,
nveths, veths, control,
ttyPaths, nttyPaths, handshakefd};
/* allocate a stack for the container */
if (VIR_ALLOC_N(stack, stacksize) < 0)
return -1;
stacktop = stack + stacksize;
cflags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|CLONE_NEWIPC|SIGCHLD;
if (userns_required(def)) {
if (userns_supported()) {
VIR_DEBUG("Enable user namespace");
cflags |= CLONE_NEWUSER;
} else {
virReportSystemError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("Kernel doesn't support user namespace"));
VIR_FREE(stack);
return -1;
}
}
if (lxcNeedNetworkNamespace(def)) {
VIR_DEBUG("Enable network namespaces");
cflags |= CLONE_NEWNET;
}
pid = clone(lxcContainerChild, stacktop, cflags, &args);
VIR_FREE(stack);
VIR_DEBUG("clone() completed, new container PID is %d", pid);
if (pid < 0) {
virReportSystemError(errno, "%s",
_("Failed to run clone container"));
return -1;
}
return pid;
}
ATTRIBUTE_NORETURN static int
lxcContainerDummyChild(void *argv ATTRIBUTE_UNUSED)
{
_exit(0);
}
int lxcContainerAvailable(int features)
{
int flags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|
CLONE_NEWIPC|SIGCHLD;
int cpid;
char *childStack;
char *stack;
if (features & LXC_CONTAINER_FEATURE_USER)
flags |= CLONE_NEWUSER;
if (features & LXC_CONTAINER_FEATURE_NET)
flags |= CLONE_NEWNET;
if (VIR_ALLOC_N(stack, getpagesize() * 4) < 0) {
VIR_DEBUG("Unable to allocate stack");
return -1;
}
childStack = stack + (getpagesize() * 4);
cpid = clone(lxcContainerDummyChild, childStack, flags, NULL);
VIR_FREE(stack);
if (cpid < 0) {
char ebuf[1024] ATTRIBUTE_UNUSED;
VIR_DEBUG("clone call returned %s, container support is not enabled",
virStrerror(errno, ebuf, sizeof(ebuf)));
return -1;
} else if (virProcessWait(cpid, NULL) < 0) {
return -1;
}
VIR_DEBUG("container support is enabled");
return 0;
}
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